I found this plugin extremely helpful for emailing me when links went bad and correcting them everywhere they appeared throughout my blog from one settings page. A search on "broken links" in this forum didn't find any discussions on this topic. Has wp.com considered incorporating this plugin in its sitewide offerings? I think it would be an invaluable tool for all wp.com authors.

Yes it would be a nice addition - there are several web based ones that will scan your site but you do need to visit their site and run the scan - not as easy as clicking on a box in your blog.

This is one I have used: http://validator.w3.org/checklink (judging from my Google search I have at least looked at some other sites also) - but you do need to configure it (be sure and check: Check linked documents recursively, recursion depth, so it will go down into your site - I also checked "hide redirects" because WordPress.COM adds some redirect junk with the sharing options) -

Also, you need to be really careful with this stuff. There was a case here about three years ago where someone ran something on her computer that scanned her WP.com blog for "bad code" and was set to automatically fixed it. For some reason, it classified all the post content as bad code, and erased nearly her whole blog before it was caught.

@auxclass: Yes, I do check periodically check my links independently, but it's not the same as getting a notification when one goes bad and being able to correct the URL or unlink the linked text everywhere I've used it with a couple of clicks.

@raincoaster: Just to reiterate to anyone reading, raincoaster's talking about something someone ran on her own which modified her blog, not something which ran inside WordPress itself. The plugin I'm talking about doesn't change links without asking, it reports to you and lets you decide whether to do anything.

(Sorry, I just don't want someone casually reading to think this plugin (or something like it wp.com might adopt) is likely to be dangerous.)

@jeffcovey - I agree it would be a nice feature - but judging from the time and CPU resources the above check took on my modest blog I suspect that WordPress.COM might be reluctant to turn that usage loose on their servers.

Maybe they could think about it as a paid upgrade to run on a regular basis.

@auxclass: You're talking about an external service which has to crawl the rendered versions of all your pages each time it runs. A plugin just has to get the links from the content of your posts/pages (ignoring links in Twitter widgets, etc., which w3.org can't distinguish), stick them in the database, update the database when a page/post is added or edited, and check the links periodically.

Few resources are needed -- a check for new/changed links as part of saving new content, and the link checking itself. WP.com has the added advantage of being able to combine everyone who's using the feature into a single database, check a link once, and send notifications to everyone who's using that URL. Shouldn't cause any server strain at all.